1. Field of the Invention
The present invention relates to a disk guide apparatus for an optical disk playback system, and more particularly, to an improved disk guide apparatus for an optical disk playback system which realizes simplified structure and decreases the number of required parts for thereby preventing erroneous insertion of the disk and which provides an oval shaped guide pin for thereby carrying out a loading/unloading operation of an optical disk with less power, thereby decreasing production cost as well as improving workability.
2. Description of the Background Art
In general, an optical disk playback apparatus denotes a device that plays back a DVD (Digital Video Disk) or a CD (Compact Disk). Depending upon disk loading methods, the disk playback apparatus varies to a tray loading type and a slot loading type.
In the tray loading type, an optical disk is placed on a plate-shaped tray which then moves back and forth to load or unload a target disk, and in the slot loading type, the disk is inserted into a slot of the optical disk playback apparatus for its loading and the disk becomes also unloaded through the slot.
A conventional disk guide apparatus for such an optical disk playback system is provided in a slot loading type optical disk playback system for thereby serving to guide the optical disk being inserted by a user.
As shown in FIGS. 1 and 2, such a conventional disk guide apparatus 100 for an optical disk playback system includes a stopper plate 10 having thereat an insertion entrance (not shown, and referred to as slot, hereinafter) of the optical disk. The stopper plate 10 includes a stepped portion 11 indented in the center thereof and formed at a front portion of a housing 2.
In rear of the stopper plate 10, there are provided a pair of slide plates 20, 20' facing against each other for thereby preventing an erroneous insertion and guiding the loading/unloading of the optical disk 1. The pair of the slide plates 20, 20' respectively have an extension toward each other in symmetry, and rack gears 21, 21' are formed on inner sides of the extended portions thereof.
A pinion gear 30 is engaged between the rack gears 21, 21' to rotate on the rack gears 21, 21' when the optical gear 1 is inserted.
Triangular guide bosses 40, 40' are hingedly fixed by a hinge pin 3 to front side portions of the slide plates 20, 20'. Guide pins 41, 41' are downwardly extended from lower edge portions of the guide bosses 40, 40'. Protrusions 42, 42' are extended from side edge portions of the guide bosses 40, 40'.
Torsion springs 50, 50' are worn on the hinge pins 33 that hingedly connect the guide bosses 40, 40' to the slide plates 20, 20'. An end of each of the torsion springs 50, 50' is hooked on a corresponding side portion of the slide plates 20, 20' and another end thereof is hooked on the corresponding protrusions 42, 42' of the guide bosses 40, 40'.
The disk loading operation of the thusly constituted conventional disk guide apparatus of the slot loading type optical disk playback system will now be described with reference to the accompanying drawings.
As shown in FIG. 3, when the optical disk 1 is inserted by a user, since the respective protrusions 42,42' of the guide bosses 40, 40' becomes hooked on each stepped portion 11 of the stopper plate 10 at an initial stage, the optical disk 1 becomes centrally positioned by the guide pins 41, 41' of the guide bosses 40, 40', so that the optical disk 1 is inserted into the optical disk playback system while maintaining its balance.
At this time, when the optical disk 1 is sidedly inserted into the center of the slot, the guide boss 40 which is primarily touched by the optical disk 1 being inserted is backwardly rotated on the hinge pin 3, whereby the guide boss 40 is released from the stepped portion 11 of the stopper plate 10. To the contrary, the protrusion 42 of the other guide boss 40 is hooked on the stepped portion 11 of the stopper plate 10, whereby the slide plates 20, 20' are prevented from moving from left to right, thereby preventing an erroneous insertion of the disk.
When the optical disk 1 is inserted into the optical disk playback system while maintaining balance at its center by the guide pins 41, 41', the guide pins 41, 41' are backwardly pushed by the optical disk 1 being inserted. Accordingly, the guide bosses 40, 40' suppresses the restoring force of the spring 50 supported by the protrusions 42, 42' formed at respective side portions of the guide bosses 40, 40 and backwardly rotates while having the hinge pins 3, 3' hingedly connected to the slide plates 20, 20' as rotational shafts, and at the same time the protrusions 42, 42' become released from the stepped portion 11 of the stopper plate 10.
In case the optical disk 1 is further inserted into the optical disk playback system, the pair of slide plates 20, 20' respectively connected to the guide bosses 40, 40' by the hinge pins 3, 3' becomes distanced by moving from each other, and the rack gears 21, 21' extended from the pair of the slide plates 20, 20' drive the pinion gear 30 by being engaged therebetween, whereby the slide plates 20, 20' becomes moving from left to right for thereby loading the optical disk 1.
However, the conventional disk guide apparatus for the slot loading type optical disk playback system requires too many parts for thereby complicating its structure, so that the complicated assembly process results in an increased production cost and the workability is significantly deteriorated.
Further, the conventional disk guide apparatus for the slot loading type optical disk playback system provides circular guide pins, and accordingly when the optical disk is inserted into the optical disk playback system, the input angle becomes large for requiring increased power, so that it is difficult to replace the disk guide apparatus with compound resin product for thereby resulting in inevitable increase of production cost.